SAN JOSE, CALIFORNIA - SEPTEMBER 1: Extreme heat advisory signs are displayed on Highway 87 message boards in San Jose, Calif., Thursday, Sep. 1, 2022. (Karl Mondon/Bay Area News Group)
As California heads into the hottest weekend of the year — with temperatures expected in the high 90s across much of the Bay Area and some inland areas forecast to hit a scorching 110 degrees or more on Monday and Tuesday — the massive demand for air conditioning is straining the state’s power grid.
Two years ago, during a similar heat wave on Aug. 14 and 15, 2020, electricity use exceeded supplies and rolling blackouts cut power to 812,000 customers around the state for up to two hours each day. Those were California’s first such “rotating outages” since 2001.
Could it happen again this weekend?
“If I had to bet, I would bet we aren’t going to have rotating outages. But it’s going to be tight,” said Severin Borenstein, a business professor at UC Berkeley and board member of the Independent System Operator (ISO), the agency that runs California’s power grid.
Every day since Wednesday, the ISO has issued a “Flex Alert,” in which it asks residents not to run large appliances like dishwashers or washing machines from 4 p.m. to 9 p.m., and to turn air conditioning to 78 degrees if possible to reduce electricity demand. Similar “Flex Alerts” are a near certainty into next week.
On Thursday, amid unusually hot weather statewide, electricity demand in California hit 47,357 megawatts — the most on any day since September 2017. There were no power interruptions in part because voluntary conservation from residents and businesses reduced demand by 1,200 megawatts, the ISO said.
But next Monday and Tuesday, demand is forecast to be higher — roughly 49,000 megawatts. The all-time record is 50,270 in July 2006.
“The hottest weather in this heat wave is still ahead of us,” said Elliott Mainzer, president of the ISO, in a video message Friday. “Electricity conservation is going to be essential in keeping the power flowing to California without interruption.”
The National Weather Service on Friday issued an “excessive heat warning” from 11 a.m. Sunday through 8 p.m. Tuesday for the East Bay’s interior mountains and valleys, the Sonoma Coastal Range, North Bay hills, and the Santa Clara Valley, including San Jose.
Similarly searing conditions are forecast in the Central Valley, Southern California and other Western states, with cooler temperatures in the 70s and 80s along the coasts.
With temperatures 10 to 20 degrees hotter than normal this week, and climate change making heat waves more severe throughout the summer, demand for air conditioning has soared. California also is in the third year of a severe drought, which has left reservoir levels low, producing less hydropower.
The state’s electricity crisis 20 years ago, which led voters to recall former Gov. Gray Davis, was sparked by lawmakers and former Gov. Pete Wilson deregulating the electricity market in 1996. That left vulnerabilities that companies like Enron took advantage of, as they withheld power from the grid to dramatically drive up prices.
More recently, however, the state’s push for renewable energy has contributed to the risk of blackouts. An increasing amount of California’s electricity, about 35% now, comes from renewable energy like solar and wind farms. That cuts smog and has helped reduce greenhouse gases, which peaked in California in 2004 and have fallen about 14% since then.
But, of course, the sun doesn’t shine at night. On very hot days, when millions of people come home from work late in the afternoon during the hottest part of the day, they crank up air conditioning. Temperatures remain high in the early evening, but solar production falls as the sun sets.
Most days, there is enough electricity from other sources, like wind farms, natural gas plants, nuclear power from the Diablo Canyon plant in San Luis Obispo County, and imports from other states. But during extreme heat waves, temperatures remain hotter for longer, and there is little power available for other states to sell.
After the two-day blackouts in 2020, Gov. Gavin Newsom ordered the ISO, the California Energy Commission and the State Public Utilities Commission to reduce the risk of future shortfalls. One of the steps taken was to require utilities like PG&E to secure more power from generating plants in and out of state. They now must have contracts for 117% of their expected peak demand, up from 115% a few years ago.
The state also has offered incentives for companies to build more large-scale battery storage so that solar power generated during the day can be stored and used at night.
In a summer outlook report published in May, the ISO noted that the state has added about 4,000 megawatts in the past year — much of that in new battery storage plants. But it remains about 1,700 megawatts short of having enough to meet the industry standard of one outage every 10 years.
Any disruption during a heat wave, like a power plant breakdown or a fire that takes out a major electrical transmission line, can result in a shortfall. On Wednesday, Newsom signed an executive order aimed at boosting supplies. It allows temporary “peaker plants” to operate, ships in port to run their engines without plugging into shore, and other steps that are usually curtailed by air pollution rules.
In addition to that, state lawmakers voted Thursday morning to allow Diablo Canyon to continue operating until 2030, five years past its proposed closure date.
Shon Hiatt, a business professor at USC, said as California keeps expanding renewable energy, it also must maintain and expand “baseline” power like hydroelectric, nuclear and geothermal.
“It’s always good to have a broad portfolio,” he said. “Any time you are too focused on one type of generation you become susceptible to bottlenecks and the weather. Germany shut down their nuclear plants and became more reliant on Russian natural gas. Then Russia turned off the gas. You don’t want to be too heavily reliant on one source or another.”
Borenstein said one long-term solution is to keep building battery storage and to require utilities to offer people cheaper electrical rates during parts of the day when summer demand is low. That would shift some power-hogging activities away from peak time.
Until then, on the hottest weeks, the public will be asked to conserve.
“It looks like we are going to have enough this weekend,” Hiatt said, “but the cushion is very thin.”
Originally published at Paul Rogers